InlinedVisitor: Migrate dom to use inlined tracing

Source/core/dom/MessagePort.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 87 matching lines @@
         start();
     }
     EventListener* onmessage() { return getAttributeEventListener(EventTypeNames::message); }
 
     // A port starts out its life entangled, and remains entangled until it is closed or is cloned.
     bool isEntangled() const { return !m_closed && !isNeutered(); }
 
     // A port gets neutered when it is transferred to a new owner via postMessage().
     bool isNeutered() const { return !m_entangledChannel; }
 
-    virtual void trace(Visitor*) override;
+    DECLARE_VIRTUAL_TRACE();
 
 private:
     explicit MessagePort(ExecutionContext&);
 
     // WebMessagePortChannelClient implementation.
     virtual void messageAvailable() override;
     void dispatchMessages();
 
     OwnPtr<WebMessagePortChannel> m_entangledChannel;
 
     bool m_started;
     bool m_closed;
 
     WeakPtrFactory<MessagePort> m_weakFactory;
 };
 
 } // namespace blink
 
 #endif // MessagePort_h